Alum, I′ron

(-ŭrn). Syn . Alu′men Fer′ricum , Sul′phas fer′ri et pot as′sæ , Fer′ri perox′idi pota io-sul′phas , ., L. Comp. K 2 SO 4 . Fe 2 (SO 4 ) 3 .24Aq. Prep. Take of peroxide of iron, 9 lbs.; sulphuric acid 14 lbs.; di olve, dilute the mixture with water, q. s., and add of pota ium sulphate, 10 lbs.; evaporate, and crystallise. Prop., . Crystals, beautiful octahedrons of a pinkish or pale violet colour. It is strongly recommended, by Dr Tyler Smith, as a chalybeate tonic, and has been used by him, at St. Mary’s Hospital with marked succe . It has also been used as a mordant, in dyeing black.— Dose , 1 ⁄ 2 gr. to 5 gr.